George hawxhurst



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GEORGE HAWXHURST, SOMERSVILLE, CALIFORNIA.

Letters Patent No. 84,489, dated December 1, 1868.

IMPROVED MODE OI PREVENTING CORROSION OF BOILER-TUBES IN- SEA-GOING-VES- SELS.

v I The Schedule referred to in these Letters Patent and maktngpart ofthe name.

To all whom it-may concern-5 Be it known that I, GEORGE HAWXHURST, ofSomersville, county of Contra Costa, State of California, have inventeda new and improved Mode of Preventingthe Destruction of Boiler-Tubes inSea-Going Vessels; and 1 do hereby declare that the following speciefication gives a full, clear, and exact description of the operations tobe performed, together with the agents used in performing the saidoperations, or accomplishmg the said object.

The nature of my invention is to provide a new mode of preventing therapid destruction of thetubes of boilers of sea-going steamers usingsurface-condensers, and from some cause, not well understood, therearises a very rapid colrosion and destruction of the tubes, which mustbe frequently replaced at, great expense.

- It is a well-known fact that surface-condensation, as now practised,has the great disadvantage of being accompanied with more or lesscorrosion or waste of the boilers, and particularly of the tubes, and astubular boilers haye become almost indispensable in sea going steamers,it is a matter of great importance to obviate'this source of trouble andexpense.

The cause of this particular corrosion is involved in mystery; andindeed the corrosion of iron in all other forms, and under variedcircumstances, has been the subject of much thought and research amongscientific men, and without unanimity of opinion.

It is therefore superfluous to describe herein the various theoriespresented, inasmuch as the object of the invention is simply to producethe practical result of obviating the practical difficulty, and, in thisconnection, has more reference to the daily duties of the engineer thanto the province .of analytical chemistry.

In my invention, the desired result is accomplished by introducing intothe boiler a solution of lime in water, commonly known as lime-water.

This material may be introduced at intervals, as required, or it may becontinuously, in small quantity,

by mechanism provided for that purpose, but it is perhaps preferable touse a globe-cock similar .to the com-- mon globe talon-cock used onsteam-engines.

The quantity of lime used to make the solution is of course to bedetermined by the amount of condensed a fair criterion for the engineerto gauge the quantity to use-taking care rather to use too much than toolittle, as, in the case of using in excess, the result of the productionof a thin scale on the tube is not objectionable.

In fact it has been common heretofore to endeavor to form a similarscale, by pumping salt water-"into. the boilers, thereby protecting thetubes to a considerable extent, but at a great expense in fuel, and withuncertain results.

But referring again to the undetermined causes of corrosion, it wouldseem that this new invention operates as an actual neutralizing-agent tothat principle in the condensed water: which causes the corrosion,

as -well as by forming a protecting scale precipitated on the surface ofthe tubes.

Having thus described my invention,.

What I claim, and desire to secure by Letters Patcut, is-- A protectionfrom corrosion, for the boilers of steam ers using surface-condensers,consisting of the solution herein described, and used substantially asset forth.

In witness whereof, I have hereunto set my hand and seal.

GEORGE HAWXHURST. [1,. s.] Witnesses:

DAVID Srronnnnr, J. L. Boom.

